NISCAIR Online Periodicals Repository Collection: IJEMS Vol.19(4) [August 2012]http://nopr.niscair.res.in/handle/123456789/14637
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Free vibration analysis of thick plates on elastic foundations using modified Vlasov model with higher order finite elementshttp://nopr.niscair.res.in/handle/123456789/14656
Title: Free vibration analysis of thick plates on elastic foundations using modified Vlasov model with higher order finite elements
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<br/>Authors: Ozgan, Korhan
<br/>
<br/>Abstract: <span style="mso-ansi-language:EN-US" lang="EN-US">This study
is concerned with the free vibration analysis of thick plates on elastic
foundation using modified Vlasov model. The effects of the subsoil depth,
aspect ratios, the ratio of subsoil depth to span of the plate and the value of
the vertical deformation parameter within the subsoil on the frequency
parameters of plates on elastic foundations are investigated. An eight-noded,
24 degrees of freedom quadrilateral finite element (PBQ8) based on Mindlin
plate theory is used for the analysis. The first six natural frequency
parameters are presented to show the effects of the parameters considered in
the study. It is concluded that the subsoil depth is more effective on the
frequency parameters of plates resting on elastic foundation than the other
parameters considered in this study.
</span>
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<br/>Page(s): 279-291Sun, 29 Jul 2012 22:58:59 GMTEstimation of the flash points of saturated and unsaturated hydrocarbonshttp://nopr.niscair.res.in/handle/123456789/14655
Title: Estimation of the flash points of saturated and unsaturated hydrocarbons
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<br/>Authors: Keshavarz, M H
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<br/>Abstract: This work introduces a novel, reliable and
simple correlation for predicting the flash point of various types of saturated
and unsaturated hydrocarbons containing cyclic and acyclic paraffins, olefins,
alkynes and aromatic hydrocarbons. It is shown that the new method is based on
the number of carbon and hydrogen atoms and some specific molecular moieties,
which can easily be used for any types of hydrocarbons. The largest available
experimental data consisting of 441 diverse hydrocarbons are used here in order
to derive and test the general correlation. For a data set containing 423 of
these
441 hydrocarbons, the root mean square (rms) and average absolute deviations
are 7.7 and 5.7 K, respectively. The estimated flash points for 18 further hydrocarbons
containing complex molecular structures have been compared with one of the best
available new group additivity methods, which give much lower values of the rms
and average absolute deviations.
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<br/>Page(s): 269-278Sun, 29 Jul 2012 22:58:59 GMTSimulation of non-linear viscoelastic behavior of cross-linked mesoporous silica aerogels by depth-sensing indentationhttp://nopr.niscair.res.in/handle/123456789/14654
Title: Simulation of non-linear viscoelastic behavior of cross-linked mesoporous silica aerogels by depth-sensing indentation
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<br/>Authors: Kucuk, Yilmaz
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<br/>Abstract: Aerogels are ultra-lightweight nanoporous materials with high thermal insulation value for industrial applications. Recently, a reinforcing process referred to as ‘crosslinking’ has been implemented to improve their mechanical properties via coating the pore structure with a nano-thin conformal polymer layer. In this study, ordered mesoporous, monolithic silica aerogels obtained by templating with a tri-block co-polymer used as surfactant, is tested by depth-sensing indentation at the room temperature, and the results are compared with simulations using the ABAQUS software package. Assuming that polymer crosslinked aerogels have non-linear viscoelastic properties due to their polymer encapsulated mesoporous structure, the Burgers model is implemented as a user-defined subroutine in the ABAQUS environment. The results clearly show that the loading-unloading curves obtained from the nanoindentation tests are in good agreements with simulation. Therefore, predictions using different loads and loading rates can be modeled by implementing Burger's model.
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<br/>Page(s): 260-268Sun, 29 Jul 2012 22:58:59 GMT<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Microstructural development on AISI 1060 steel by FeW/B<sub>4</sub>C composite coating produced by using tungsten inert gas (TIG) process</span>http://nopr.niscair.res.in/handle/123456789/14653
Title: <span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Microstructural development on AISI 1060 steel by FeW/B<sub>4</sub>C composite coating produced by using tungsten inert gas (TIG) process</span>
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<br/>Authors: Islak, Serkan; Buytoz, Soner; Karagöz, Muzaffer
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<br/>Abstract: <span style="mso-ansi-language:
EN-US" lang="EN-US">This study discusses the effects of B<sub>4</sub>C addition on the
morphologies of primary carbides and eutectic colonies in FeW weld-surfacing
alloys.<span style="mso-ansi-language:EN-US;mso-fareast-language:
ZH-TW" lang="EN-US"> Results reveal that a series of FeW <span style="mso-ansi-language:EN-US" lang="EN-US">weld-surfacing<span style="mso-ansi-language:EN-US;mso-fareast-language:ZH-TW" lang="EN-US"> alloys with
different B<sub>4</sub>C contents are successfully fabricated onto AISI 1060
steel by using <span style="mso-ansi-language:EN-US;
mso-bidi-font-weight:bold" lang="EN-US">tungsten inert gas (TIG) <span style="mso-ansi-language:EN-US;mso-fareast-language:ZH-TW" lang="EN-US">arc welding. <span style="mso-ansi-language:EN-US;mso-bidi-font-weight:bold" lang="EN-US">SEM
observations show that the obtained coating sheet has a smooth and uniform
surface, as well as a metallurgical combination with the AISI 1060 steel substrate
without cracks and pores at the interface. Fe<sub>23</sub>(C,B)<sub>6</sub>, Fe<sub>3</sub>(C,B),
FeW<sub>2</sub>B<sub>2</sub> and FeW<sub>3</sub>C boride and carbides are
determined in the microstructure. The microhardness values of the coating
results show a difference <span style="mso-ansi-language:
EN-US" lang="EN-US">depending on the<span style="mso-bidi-font-weight:bold"> rate of B<sub>4</sub>C
and coating conditions. The maximum microhardness value of the coating
is about 1095 HV.<span style="mso-bidi-font-weight:bold">
</span></span></span></span></span></span></span></span></span></span>
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<br/>Page(s): 253-259Sun, 29 Jul 2012 22:58:59 GMT